Road marking apparatus



Jul 18, 1950 G. A. FISHER ROAD MARKING APPARATUS 2 Sheets-Sheet 1 Filed May 24, 1946 INVENTOR GEORGE A. FISHER July 18, 1950 FISHER 2,515,865

ROAD MARKING APPARATUS Filed May 24, 1946 2 Sheets-Sheet 2 41 40 I 58 4 4. /I '1, 35 57 35 .77 h :75 -176 .19 56 32 INVENTOR GEORGE A.F|sHER Patented July 18, 1950 UNITED STATES. PATENT OFFICE 2,515,865 ROAD MARKING APPARATUS George A. Fisher, Pittsburgh, Pa.

Application May 24, 1946; Serial No. 672,138

This invention relates broadly to a spraypainting device and, in particular, to an automotive vehicle for painting zone stripes on roadways,

' parking areas, airports and the like while travel- Claims. (01. 9112) of uniform thicknesswith sharply defined edges. 10 A recent development in highway marking stripes,'

furthermore, has made the requirement for ex- .actitude in the thickness of the layer of paint considerably more stringent. This-is the luminous marking stripe which is made by depositing v glass beads or other reflecting particleson a paint sufficient depth to be firmly adherent If the paint layer is too thick, the beads are immersed and covered over by the paint. The beads may be as small as .030" or as large as .120".

If the paint layer is. too ,20

I have invented a, novel apparatus for applying marking stripes to roadways and the like which is capable of laying a stripe of the exact thickness required for satisfactory deposition of refleeting particles.

tank having an air compressor and a pump mounted thereon as well as an engine for driving it. The vehicle is driven at a speed proportional In a preferred embodiment, .I provide an automotive vehicle including a paint to that at which the pump operates so that the delivering paint in a substantially constant stream, as well as a novel form of gun or spray head capable of laying a stripe with sharply defined edges, without the use of blinds or side guards.

For a complete understanding of the invention, reference is made to the accompanying drawings illustrating a present preferred embodiment. In the drawings,

Figure 1 is a side elevation of the machine;

Figure 2 is an end elevation, such as wouldbe seen by looking from the left of Figure 1;

Figure 3 is a plan view of the pump; v

Figure 4 is a, longitudinal section therethrough Figure 5 is a transverse section through the gun or spray head; and

Figure 6 is. a longitudinal section through one of the nozzles of the paint gun.

Referring in detail to the drawings, my roadmarking vehicle indicated generally at IU comprises a frame or chassis l I having a front wheel l2 and rear wheels l3,mounted thereon and steeringhandles 14 extending rearwardly therefrom. The wheels are fitted with pneumatic tires. A paint tank l5 of suitable capacity is mounted On the frame II. The tank is preferably fabricated from plate so as to provide a support for the remaining apparatus.

An internal combustion engine I6 is mounted on the tank I5 toward the front end thereof. The exhaust pipe from the engine, indicated at H, is 'a flexible tube and extends forwardly and downwardly in front of the vehicle terminating in a nozzle l8 adapted to blow dust and dirt oil of a strip of the roadway along which the vehicle travels. A compressor I9 mounted adjacent the engine It is driven thereby through a belt drive. The compressor serves'to accumulate a supply of air.in a tank i911. under suitable pressure for atomizing paint supplied to a paint gun in a manner which will be explained later. a

A pump 20 is mounted on the tank l5 next to the compressor l9 and is belt-driven by a pulley on the compressor. The pump is a multiplecylinder diaphragm pump adapted to deliver a substantially constant supply of paint and the detailed construction thereof will be described hereinafter. For the present, it will suffice to state that the pump draws paint from the tank l5 through a connection 21 and branches 21a and delivers itthrough connections 22 to a terminal fitting 23. These branches and connections are provided with suitable check valves 22a. The tank l9a is also connectedto this fitting.

A traction drive 24 is provided for one of the wheels I3 as] shown in Figure 2 and comprises a belt trained around a pulley onthe shaftof the pump 20 and a pulley secured to the wheel. The operation of the pump and travel of the vehicle are thus coordinated or correlated so that a predetermined amount of paint is delivered by the pump for a given travel of the vehicle.

A paint gun 25 is mounted on the frame H. Flexible pipelines 2B and 2'! supply paint and air, respectively, to the gun. Thesupply of paint to the gun is controlled by a valve 28 on the handles I4. This valve is connected by suitable piping (not shown) to the fitting 23 and serves taken along the plane of line IV-IV' of Figure 3; in one position to deliver the output of the pump engine I6 is also mounted on the handles l4.

The pump 20 comprises a box-like frame 31 having a plurality of diaphragm chambers 32 arranged in spaced opposed pairs. A drive shaft 33 journaled in the two opposite sides ofsthe frame extends between ithe chambers of each pair.

"Each chamber hasan inlet 34 and an outlet 35 and is provided with a flexible diaphragm 36., A reciprocating plunger extends into each diaphragm chamber. and is, provided with spaced discs 38 havingconvex surfaces adjacent the diaphragm for deforming it in opposite directions. .The plunger of one diaphragm chamber of each pair has an extension 39 pivoted to theplunger Wo f the opposed chamber and to a connecting rod The connecting rods are actuated by eccen- .,trics 4| on the shaft 33.

Theplungers 31 with their discs 38 constitute actuators for the diaphragms. The eccentrics 4| are so spaced angularly on the shaft that one of the diaphragms makes a compression movement on each quarter, -turn of the shaft. That is to say, the operation {of the diaphragm is so timed that a substantially :continuous delivery of paint is maintained.

It will be understood that, as the diaphragms are detormed on the suction stroke, paint is .drawn from the tankthrough the connectionv 2|, one

.pf thebranches 2m and an inlet check valve 22a,

adjacent the inlet 34. On thecompression stroke,

the .paint is forced through the outlet 35 and theoutlet check valve 22a into one of the con-. ..nections 22 leading to the terminal fittingv 23.

The spray gun 25, as indicated in Figure 5, comprises. a body 42 to which one of the paint lines v26 .is connected. A paint nozzle 43 held against the body 42 by a cap 44 secured thereto is adapted ,to discharge paint into a mixing chamber 45 ,formed in the cover.

air chamber 45a surrounding the nozzle 43 to The cover also provides an which the air line 21 is connected. Air ports 41 in the wall of the nozzle 43 between the chambers v 45a and 46 admit atomizing airfrom the latter to the former.

The flow of paint through the nozzle 43 is controlled by a needle valve 48. This valve is op- A hand '1' throttle 30 for controlling the fuel supply of the 4 output of the pump to be delivered to gun 25 or returned to the tank I5.

A T 54 is connected to the outlet of the mixing chamber by a nipple 46. Elbows 55 connected to the T are provided with nozzles 56. As shown in Figure 6, each nozzle comprises a tube closed at one end having an arcuate radial slot 51 milled in the closed end and intersecting the bore. This -causes "the. nozzle to discharge 'a fiat brushlike spray having a sharply defined edge on one side. As shown in Figure 2, the sprays from the two nozzles intersect or overlap, both sprays being directed downwardly and angularly toward each other. By this arrangement, it is possible to "apply a stripe of the desired width having sharply defined edgeswithout using side guards or blinds as has been necessary heretofore.

I vIt-yvill be apparent from the foregoin description that the invention provides a simple andefiicient road-marking apparatus capable of rapidly, applying a stripe of precisely the desired thickness ,to suit, it for the application of reflectling particles. The thickness of the stripe applied, of course, is determined by the volume of paint delivered by, the pump for ,a given distance traveled by the vehicle. This may be controlled [assuring uniform coverage and the nozzles are such as to keep the edges of the stripe straight and true, vThe,discharge of paint from the. gun

. is readily controlled by a simple transfer valve erated by a diaphragm 49 extending across a chamber 50 formed partly in the body 42 and' partly in a cover 5| secured thereon. The lower face of the diaphragm 50 is subject to the back pressure of the paint in the line 26. This presi turning this sleeve. It will be apparent that when the back pressure of the paint in the line 26 is suff cient to overcome the force of the spring on the diaphragm, the valve 48 will be opened to admit paint into the mixing chamber45. In this Way, it is possible 'to control the discharge of paint from the gun by the valve 28 which causes the mounted on the steering handles for the convenience of the operator. The engine exhaust is utilized to blow dust and dirt off the roadway "ahead of the gun, thus assuring a clean surface .for the application ofpaint.v

7 Although 'I'have illustrated and describedjbut a preferred embodiment of the invention, it will be .recpg iz d that 'changes in the details. dis- ;olosed may be made without departing from the "(spirit of the invention or the scope of the appended claims.

1. Apparatu's'for marking roads with a uniform thickness of paint comprising a wheeled vehicle having mounted thereon a paint reservoir, a paint gun to marl; the road, an air compressor to supply compressed air to the gun, a

7 ,pump to force paint from the reservoir into the 'gun,' a motor, .a driving connection between the motor and a Wheel of the vehicle, and a driving connection between .the motor and the pump whereby the vehicle and pump are driven at speeds varying in constant proportion as the speed of the motor varies and the gun thereby receives paint in quantities varying with the speed of-the vehicle, said gun comprising means to release said varying quantities of paint at a substantially constant pressure into a stream of cor'npressedair from the compressor, thus forming a mixture in which the paint content varies in proportion to the speed of the vehicle.

2. Apparatus for marking .roads with a uniform thickness of paint comprising a wheeled vehicle having mounted thereon a paint reservoir, a paint gun to mark the road, an air compressor to supply compressed air to the gun, a positive feed pump to force paint in an even fiow from the reservoir into the gun, a motor, a driving connection :between the motor and a Wheel of the vehicle, and a driving connection beween the motor and the pump whereby the vehicle and pump: are

driven at speeds varying in constant proportion sure into a stream of compressed air from the compressor, thus forming a mixture in which the paint 'content'varies in proportion to the speed of the vehicle. 3

-' 3. Apparatus for marking roads with a unilformly thick coating of paint comprising a wheeled vehicle having mounted thereon a paint reservoir, a, paint gun to mark the road, an air compressor to supply compressed air to the gun, a pump to force paint from the reservoir into ,the, gun, a motor, a driving connection between the motor and a wheelof the vehicle and a driving connection between. the motor and the pump whereby the vehicle and pump are driven by the motor at speeds varying in constant proportion as the speed of the motor varies, said gun comprising a passage therethrough connected to the compressor to receive a stream of compressed air, a chamber in the gun connected to the pump to receive paint from the pump, an outlet from the chamber into the said passage, and a valve in the outlet biased to release the paint 7 from the chamber at a substantially constant predetermined pressure, whereby a mixture of paint and air is formed in the gun having a paint content which varies in direct proportion to the speed of the vehicle.

4. Apparatus for marking roads with a unif or mly thick coating of paint comprising a wheeled vehicle having mounted thereon a' paint reservoir, a paint gun to mark the road, an air compressor to supply compressedwair to the gun, a positive feed pump to force paint from the reservoir into the gun, a motor, a driving connection between the motor and a wheel of the vehicle and a driving connection between the motor and the pump whereby the vehicle and pump are driven by the motor at speeds varying in constant proportion as the speed of the motor varies, said gun comprising a chamber in the gun connected to the pump to receive paint from the pump, an outlet from the chamber passage, a valve in the outlet, a diaphragm forming one wall of 'the chamber and attached to the valve to move the valve from the outlet as the pressure of paint in the chamber deflects the diaphragm, biasing means opposing movement of the diaphragm and valve in response to pressure of paint in the chamber whereby paint pumped into the chamber at varying rates is released from the chamber at a substantially constant predetermined pressure, and a passage through the gun into which the chamber outlet opens and which is connected to the compressor to receive a stream of compressed air, whereby a mixture of paint and air is formed in the gun having a paint content which varies in direct proportion to the speed of the vehicle. v

5, Apparatus for marking roads with a uniformly thick coating of paint comprising a wheeled vehicle having mounted thereon a paint reservoir, a paint gun to mark the road, an air compressor to supply compressed air to the gun, a positive feed pump to force paint from the reservoir into the gun, a motor, a driving connection between the motor and a wheel of the vehicle and a driving connection between the motor and the pump whereby the vehicle and pump are driven by the motor at speeds varying in constant proportion as the speed of the motor varies, said gun comprising a chamber in the gun connected to the pump to receive paint from the pump, an outlet from the chamber passage, a valve in the outlet, a diaphragm forming one wall of the chamber and attached to the valve to move the valve from the outlet as the pressure of paint in the chamber deflects thediaphragm, a spring engaging the valve to oppose movement of the diaphragm and valve in response to pressure of paint in the chamber so that paint pumped into the chamber at varying rates is released from the chamber at a substantially constant predetermined pressure, a member adjustably mounted in the gun and engaging the spring in order to adjust said predetermined pressure, and a passage through the gun into which the chamber outlet opens and which is connected to the compressor to receive a stream of compressed air, whereby a mixture of paint and air is formed in the gun having a paint content which varies in direct proportion to the speed of the vehicle.

6. Apparatus for marking roads with 'a uniformly thick coating of paint comprising a wheeled vehicle having mounted thereon a paint reservoir, a paint gun to mark the road, an air compressor to supply compressed air to the gun, a pump to force paint from the reservoir into the gun, a motor, @a driving connection between the motor and a wheel of the vehicle and a driving connection between the motor and the pump, whereby the vehicle andpump are driven by the motor at speeds varying in constant proportion as the speed of the motor varies, said pump being a multi-chambered diaphragm pump, whereby the paint is positively fed to the gun in a smooth flow and at a rate directly proportional to the speedof the pump and of the vehicle, said gun comprising means to receive paint in varying quantities from the pump and to release it at a substantially constant pressure into a stream of compressed air from the compressor, thus forming a mixture in which the paint content varies in proportion to the speed of the vehicle.

'7. Apparatus for marking roads with a uniformly thick coating of paint comprising a wheeled vehicle having mounted thereon a paint reservoir, a paint gun to mark the road, an air compressor to supply compressed air to the gun, a pump to force paint from the reservoir into the gun, a motor, a driving connection between the motor and a wheel of the vehicle and a driving connection between the motor and the pump, whereby the vehicle and pump are driven by the motor at speeds varying in constant proportion as the speed of the motor varies, said pump comprising a plurality of diaphragm chambers arranged in opposite pairs, a diaphragm and an actuator therefor in each chamber, and an eccentric shaft extending between the opposed chambers for driving said actuators, whereby the paint is positively fed to the gun in a smooth flow and at a rate directly proportional to the speed of the pump and of the vehicle, said gun comprising means to receive paint in varying quantities from the pump and to feed it at a substantially constant pressure into a stream of compressed air from the compressor, thus forming a mixture in which the paint content varies in proportion to the speed of the vehicle.

8. A paint gun adapted to receive varying quantities of paint and to mix the paint at a constant pressure with a stream of compressed air, comprising a chamber to receive a forced 'fiow of paint, an outlet from the chamber and a valve controlling said outlet, said valve being biased to release the paint forced into the chamber at a substantially constant predetermined pressure, a passage through the gun to receive a stream of compressed air, said chamber outlet opening into said passage to release paint into the passage, whereby varying quantities of paint may be pumped into the gun and fed at a substantially constant pressure into a stream of compressed air to form a spray.

9. A paint gun adapted to receive varying quantities of paint and to mix the paint at a constant pressure with a stream of compressed air, comprising a, chamber to receive a forced flow of paint, an outlet from the chamber, a valve in I the outlet, a diaphragm forming one wall of the chamber and attached to the valve to move the valve from the outlet as the pressure of paint in the chamber deflects the diaphragm, biasing means opposing movement of the diaphragm in response to pressure of the paint in the chamber, whereby paint is released from the outlet at a substantially constant predetermined pressure, a passage through the gun to receive a stream of compressed air, said chamber outlet opening into said passage to release paint into the passage, whereby varying quantities of paint may be pumped into the gun and fed at a substantially constant pressure into a stream of compressed air to form a spray.

10. A spray gun adapted to receive varying quantities of paint and to mix the paint at a constant pressure with a stream of compressed air, comprising a chamber for paint received from the pump, an outlet from the chamber, a valve adapted to close the outlet, a diaphragm forming a wall of the chamber and attached to the valve to move the valve from the outlet as the pressure of paint in the chamber deflects the diaphragm, biasing means opposing movement of the diaphragm in response to pressure of paint in the chamber, whereby paint may be pumped through the chamber at varyin rates but is :released from the chamber at a substantially constant predetermined pressure, means to adjust the biasing means to vary the predetermined pressure, a passage through the gun to receive a stream of compressed air, said chamber outlet opening into said passage to release paint into the passage, whereby varying quantities of paint may be pumped into the gun and fed at a substantially constant pressure into a stream of compressed air to form a spray.

GEORGE A. FISHER.

REFERENCES crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,380,769 Carlson June 7, 1921 1,445,844 Mueser Feb. 20, 1923 1,787,583 Larson Jan. 6, 1931 1,800,413 Smith Apr. 14, 1931 1,811,557 Ove June 23, 1931 2,005,107 Phillips et a1. June 18, 1935 2,044,558 Ball June 16, 1936 2,076,370 Hollingshead Apr. 6, 1937 2,278,948 Rodoli et :al. Apr. 7, 1942 2,284,443 Paradise May 26, 1942 FOREIGN PATENTS Number Country Date 14,127 Great Britain Aug. 15, 1912 255,427 Great Britain Oct. 3, 1927 Certificate of Correction Patent No. 2,515,865 July 18, 1950 GEORGE A. FISHER It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 55, for 45a and 46 read 45 and 45a; column 7, line 34, for the word spray read paint;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 17th day of October, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

